Is Water Hard or Soft
Standardizing the approximately 0.01M EDTA requires one to pipet 50-mL portions of the Standard (CaCl2) calcium chloride solution to three 250 milliliter volumetric flasks. Afterwards append five droplets of Eriochrome Black T indicator solution, 5-mL of NH3-NH4Cl buffer solution followed by five droplets of magnesium-EDTA convoluted solution. This should then be accompanied by a titration with just about 0.01 molar of the EDTA solution. After doing so, calculate the molarity for EDTA from the data obtained for each titration. Work out the average of these values.
Obtain a sample bottle of approximately 500-mL deionized water and pipet three portions of fifty-milliliter portions into every single volumetric flask. Then input five milliliters of the buffer solution into every, trailed by five dribs of the indicator and lastly five droplets 5 drops of the EDTA intricate solution.
Perform a titration using the EDTA solution that was hitherto standardized.
Compute the aggregate hardness of the sample of water as parts per million (ppm) of calcium carbonate (CaCO3).Ensure to report to every group member the values of each of the three trials and the average value in the findings (Bauer et al., 2009).
Add 50-mL of the three samples of water to be tested to three separate beakers and label them i.e. boiled deionized water, tap water, and boiled tap water. Add 2 drops of buffer and 1 drop of indicator solution to each sample and stir. Pour the samples again in three separate burettes. In three separate beakers, add EDTA and titrate with the water samples until the color changes from purple to blue. Repeat the procedure three times recording the findings. The calcium standard is conveyed as milligrams of Calcium carbonate. The ratio of the quantity of EDTA droplets should be used from the identified to the unidentified in determination of the hardness of the three samples of water. Compute the total water hardness of the three water samples in parts per million of calcium carbonate as in the previous procedure (Bauer et al., 2009).
Works Cited
Bauer, R., Birk, J., Sawyer, D. Laboratory Inquiry in Chemistry, 3rd ed.; Brooks/Cole Cengage Learning: Belmont, 2009.
